JP2001240698A - Additive, polyolefin resin composition and molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an additive exhibiting excellent dispersibility to various kinds of polyolefin resins and therefore allowing to reduce an amount added to the polyolefin resins and capable of economically providing polyolefin resin compositions excellent in transparency and molded products thereof. SOLUTION: This additive is characterized by including a dibenzylidenesorbitol-based compound represented by general formula (1) (wherein, R1 to R5 and R'3 to R'5 denote each an atom or a group selected from the group composed of hydrogen atom, a halogen atom, a 1-8C alkyl group and a 1-8C alkoxy group, independently) and zinc behenate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to additives, and more particularly to additives for polyolefin resins and polyolefin resin compositions. More specifically, the present invention relates to an additive useful as a crystal nucleating agent for a polyolefin resin, a polyolefin resin composition and a molded article using the same.

[0002]

BACKGROUND OF THE INVENTION Dibenzylidene sorbitols are useful for polyolefin resins, especially polyethylene, polypropylene or copolymers based on them.
It is known that a small amount of the compound has an effect of improving the transparency of the resin, and is a useful compound as an additive for a resin in the field of molding such as various containers requiring transparency. It is also known that the compound is useful as a gelling agent for various organic solvents.

However, since dibenzylidene sorbitols are expensive, it has been desired to obtain a polyolefin resin having high transparency with a small amount of dibenzylidene sorbitol. The dibenzylidene sorbitol used as an additive for the polyolefin resin is usually added to the polyolefin resin in the form of a fine powder. For this reason, the bulk specific gravity is large and the transferability is poor, powdering is likely to occur, the fluidity of the particles is poor, and the pipes and hoppers are easily clogged,
In addition to various handling problems such as easy aggregation during transportation or storage, poor dispersibility in the resin, so-called lumps, and nuclei equivalent to the added amount due to non-uniform dispersion. There was a problem that the agent effect could not be obtained.

On the other hand, a mixture containing a diacetal powder such as dibenzylidene sorbitol and a binder is mixed at a temperature higher than the melting point or softening point of the binder and lower than the melting point of the diacetal,
It has been proposed to form the resulting compound into granules (WO 98/33851). The present invention aims to improve the apparent specific gravity and dispersibility by forming a diacetal powder into a tablet using a binder, but has a problem that the preparation process is complicated.

The inventor of the present invention has conducted intensive studies in view of the above circumstances. As a result, an additive containing a specific dibenzylidene sorbitol compound and zinc behenate has excellent dispersibility in a polyolefin resin. The present inventors have found that a polyolefin resin molded article having high transparency can be produced and that the amount of expensive dibenzylidene sorbitols can be suppressed, and the present invention has been completed.

[0006]

An object of the present invention is to provide an additive for a polyolefin resin having excellent dispersibility in a polyolefin resin, and to provide a molded article having high transparency containing the additive for a polyolefin resin. An object is to provide a polyolefin resin composition and a molded article that can be formed.

[0007]

SUMMARY OF THE INVENTION The additive of the present invention is characterized by containing a dibenzylidene sorbitol compound represented by the following general formula (1) and zinc behenate.

[0008]

Embedded image

(Wherein, R _{1 to} R ₅ and R ′ _{1 to} R ′ ₅ each independently represent a hydrogen atom, a halogen atom,
Or an atom or group selected from the group consisting of an alkyl group having 1 to 8 carbon atoms and an alkoxy group having 1 to 8 carbon atoms. ).

In the present invention, the benzylidene sorbitol compound is 1,3-2,4-di-
p-methylbenzylidene sorbitol or 1,3-
Also preferred is 2,4-di-p-ethylbenzylidene sorbitol. It is also preferable that the additive contains 0.1 to 100 parts by weight of zinc behenate based on 100 parts by weight of the dibenzylidene sorbitol compound. Further, it is preferable that the additive is for a polyolefin resin.

Further, the polyolefin resin composition of the present invention is characterized in that the above additive is contained in an amount of 0.05 to 1.0 part by weight based on 100 parts by weight of the polyolefin resin.

In such a polyolefin resin composition, it is also preferable that the polyolefin resin is a polypropylene resin. Further, the molded article of the present invention is obtained by molding the above-mentioned polyolefin resin composition.

[0013]

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the present invention will be described specifically. <Additive> The dibenzylidene sorbitol compound contained in the additive of the present invention is represented by the following general formula (1).

[0014]

Embedded image

(Wherein, R _{1 to} R ₅ and R ′ _{1 to} R ′ ₅ each independently represent a hydrogen atom, a halogen atom,
Or an atom or group selected from the group consisting of an alkyl group having 1 to 8 carbon atoms and an alkoxy group having 1 to 8 carbon atoms. ).

The dibenzylidene sorbitol compounds represented by the above general formula (1) include dibenzylidene sorbitol; 1,3-2,4-dibenzylidene sorbitol, 1,3-2,4-di (p-methyl Benzylidene) sorbitol, 1,3-2,4-di (p-ethylbenzylidene) sorbitol, 1,3-2,4-di (p-chlorobenzylidene) sorbitol, 1,3-2,4-bis (dimethylbenzylidene) ) Compounds having the same benzylidene group, such as sorbitol; 1,3-benzylidene-
2,4-p-methylbenzylidene sorbitol, 1,3
-Benzylidene-2,4-p-ethylbenzylidenesorbitol, 1,3-benzylidene-2,4-p-chlorobenzylidenesorbitol, 1,3-p-methylbenzylidene-2,4-benzylidenesorbitol, 1,3-
p-methylbenzylidene-2,4-p-chlorobenzylidenesorbitol, 1,3-p-methylbenzylidene-
2,4-p-ethylbenzylidene sorbitol, 1,3
-P-ethylbenzylidene-2,4-benzylidenesorbitol, 1,3-p-ethylbenzylidene-2,4-
Compounds having different types of benzylidene groups such as p-methylbenzylidene sorbitol and 1,3-p-ethylbenzylidene-2,4-p-chlorobenzylidene sorbitol are exemplified.

In the above formula (1), R _{1 to} R ₅ and R ′ _{1 to} R ′ ₅ each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. More preferably, it represents a selected atom or group.

Among them, in the present invention, 1,3-2,4-
Di-p-methylbenzylidene sorbitol or 1,3
It is particularly preferred to use -2,4-di-p-ethylbenzylidene sorbitol.

Such benzylidene sorbitol compounds may be used alone or in combination of two or more. The additive of the present invention contains the above-mentioned dibenzylidene sorbitol compound and zinc behenate. Such an additive of the present invention contains zinc behenate in an amount of 0.1 to 100 parts by weight, preferably 0.2 to 50 parts by weight, based on 100 parts by weight of the dibenzylidene sorbitol compound.
It is desirable that the content be 30 parts by weight, more preferably 0.3 to 30 parts by weight, particularly preferably 1 to 10 parts by weight.

The method for preparing the additive of the present invention is not particularly limited. For example, the additive may be prepared by simply mixing a powder of a dibenzylidene sorbitol compound and a powder of zinc behenate. It may be prepared by stirring and mixing a dibenzylidene sorbitol compound and zinc behenate at a temperature that is equal to or higher than the melting point of zinc behenate and lower than the melting point of the dibenzylidene sorbitol compound, Furthermore, it may be prepared by dispersing a powder of a dibenzylidene sorbitol compound and a powder of zinc behenate in alcohol or the like.

Such additives are excellent in powder fluidity,
Less powdering and good powder properties can be expected. Also,
Such an additive of the present invention can be suitably used particularly as an additive for a polyolefin resin. When the additive of the present invention is used as an additive for a polyolefin resin, it exhibits excellent dispersibility in various polyolefin resins, can reduce the amount of additives used in the polyolefin resin, and has an excellent polyolefin resin composition. Goods can be provided at low cost. <Polyolefin resin composition> The polyolefin resin composition of the present invention contains the above additives in an amount of 0.05 to 1 part by weight, preferably 0.1 to 0.5 part by weight, based on 100 parts by weight of the polyolefin resin.

The polyolefin resin constituting the polyolefin resin composition of the present invention is, for example, one having 2 to 2 carbon atoms.
6, α-olefin homopolymers and copolymers, and specific examples thereof include polypropylene, low-density polyethylene, high-density polyethylene, linear polyethylene, and ethylene-propylene copolymer. Is preferably used.

When the polyolefin resin is a polypropylene resin, examples of the polypropylene resin include a propylene homopolymer and a copolymer of propylene and an α-olefin other than propylene. Tic polypropylene, isotactic polypropylene, propylene-ethylene random copolymer, propylene-ethylene block copolymer, ethylene-propylene-butene copolymer, and the like.
When the polypropylene-based resin is a copolymer of propylene and an α-olefin other than propylene, the component unit derived from the α-olefin other than propylene in the polypropylene-based resin is 50 mol% or less, preferably 30 mol% or less.
Desirably, it is at most 15 mol%, more preferably at most 15 mol%.

It is preferable that the polyolefin resin used in the present invention is a polypropylene resin because the transparency of a molded article obtained from the polyolefin resin composition is particularly improved.

The polyolefin resin composition of the present invention can be prepared by blending the polyolefin resin and the above-mentioned additive of the present invention by known blending means such as melt kneading.

The polyolefin resin composition of the present invention may be prepared by preparing a polyolefin resin composition containing the above-mentioned additive of the present invention at a high concentration as a masterbatch, and then adding it to the polyolefin resin. . Since the additive of the present invention is excellent in dispersibility, a molded article obtained by molding the polyolefin resin composition of the present invention can also be produced by directly adding the master batch to the polyolefin resin in the molding step.

The polyolefin resin composition of the present invention may contain various additives as necessary. Examples of the additives include a phenolic antioxidant, a phosphorus antioxidant, and calcium stearate. And the like, neutralizing agents, antistatic agents, flame retardants, processing aids, pigments, fillers, foaming agents, heavy metal deactivators, and the like. When preparing a polyolefin resin composition using a masterbatch as described above, such an additive may be contained in the masterbatch and used.

In the polyolefin resin composition of the present invention, the above-mentioned additive of the present invention is uniformly dispersed without condensing in the resin. Therefore, according to the present invention, the amount of the additive used for the polyolefin resin can be reduced, and an excellent polyolefin resin composition can be prepared at low cost. Further, the polyolefin resin composition of the present invention,
Since the above-mentioned additive of the present invention is uniformly contained, a molded article having excellent crystallinity at the time of molding, and having excellent transparency and strength can be provided.

The polyolefin resin composition of the present invention can be appropriately molded by a known method for molding ordinary polyolefin. <Molded article> The molded article of the present invention is obtained by molding the above-described polyolefin resin composition of the present invention. Examples of the molding method include injection molding, extrusion molding, blow molding, and injection blow molding. The shape of the molded article is not particularly limited, and it can be obtained by molding into a shape suitable for the purpose, such as a bottle, a container, a plate, a sheet, and a film.

Such a molded article is excellent in transparency and strength, and particularly excellent in transparency.

[0031]

According to the present invention, an additive having excellent dispersibility in various polyolefin resins can be provided. Further, since the additive of the present invention is excellent in dispersibility, the amount of addition to the polyolefin resin can be reduced, and a polyolefin resin composition and a molded article excellent in transparency can be economically provided.

[0032]

EXAMPLES Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples.

[0033]

Examples 1-4 Preparation and molding of resin composition Powder of 1,3-2,4-di-p-methylbenzylidene sorbitol (hereinafter referred to as "nucleating agent A", Mitsui Chemicals, Inc.)
And zinc behenate powder were mixed at the mixing ratios shown in Table 1 using a ball mill at room temperature for 1 hour to prepare additives.

Next, a polypropylene resin, the total amount of the obtained additives, a phenolic antioxidant (hereinafter referred to as “additive B”), and a phosphorus-based antioxidant (hereinafter referred to as “additive C”) And calcium stearate in a blending ratio shown in Table 1 by a blender,
Using a single screw extruder (GMZ50-32, manufactured by GM Engineering Co., Ltd.), 260 ° C., screw rotation speed:
80 rpm, screen mesh: 60/100/60
Under the conditions described above, kneading and extrusion were performed to prepare pellets of the resin composition.

Next, using the obtained pellets, a molding machine (J100S, 100 ton, manufactured by Nikko), a molding temperature of 190 ° C. and a molding temperature of 50 using a flat mold (2 mm).
Under a condition of ° C., a flat plate having a thickness of 2 mm was injection-molded.

Using the obtained flat plate as a sample, the haze value was measured using a tester (1001DP) manufactured by Nippon Denshoku Industries Co., Ltd. Table 1 shows the results.

[0037]

Comparative Example 1 An additive containing a nucleating agent A was prepared in the same manner as in Example 1 except that zinc behenate powder was not used.

Next, using this, pellets of the polypropylene resin composition were prepared in the same manner as in Example 1, flat plates were injection molded, and the haze value was measured. Table 1 shows the results.

[0039]

[Table 1]

From the above Examples and Comparative Examples, the molded articles obtained in Examples 1 to 4 using an additive consisting of a dibenzylidene sorbitol derivative and zinc behenate showed only the same amount of the dibenzylidene sorbitol derivative. It was found that the haze value was lower than that of the molded product obtained in Comparative Example 1 and the transparency was excellent.

Continuation of the front page (72) Inventor Mineo Kobayashi 3-7-2 Nihonbashi Honcho, Chuo-ku, Tokyo Mitsui Chemical Fine Co., Ltd. F-term (reference) 4F071 AA14 AA20 AC09 AC19 AE22 AF14 AF30 AH05 BC01 BC03 BC04 4J002 BB031 BB051 BB121 BB141 BB151 EG047 EL106 FD030 FD206 FD207

Claims (7)

[Claims] An additive comprising: a dibenzylidene sorbitol compound represented by the following general formula (1); and zinc behenate; (Wherein, R _{1 to} R ₅ and R ′ _{1 to} R ′ ₅ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 8 carbon atoms, or an alkoxy group having 1 to 8 carbon atoms. Represents the selected atom or group). 2. The dibenzylidene sorbitol compound is
The additive according to claim 1, which is 1,3-2,4-di-p-methylbenzylidene sorbitol or 1,3-2,4-di-p-ethylbenzylidene sorbitol. 3. Dibenzylidene sorbitol compound 10.
The additive according to claim 1, comprising 0.1 to 100 parts by weight of zinc behenate based on 0 parts by weight. 4. The additive is for a polyolefin resin,
The additive according to claim 1. 5. A polyolefin resin based on 100 parts by weight,
The additive according to any one of claims 1 to 4, wherein the amount of the additive is 0.05 to
A polyolefin resin composition containing 1.0 part by weight. 6. The polyolefin resin composition according to claim 5, wherein the polyolefin resin is a polypropylene resin. 7. A molded article obtained by molding the polyolefin resin composition according to claim 5 or 6.